Moonlight currently is made up of a few components:
- Mono Runtime (cross platform, works on many platforms, including PowerPC and OSX)
- Graphics engine (cross platform)
- Video engine (cross platform)
- Browser gate (currently only supports Firefox)
- Windowing system integration (currently only supports X11)
There have been discussions about writing more browser gateways for new browsers, but so far it has not been a priority. If Moonlight were to be ported to the Mac, a gate to Safari would be necessary.
Currently Moonlight is very tied to the X11 implementation, so that piece would also have to be decoupled to work on other windowing systems.
It should be relatively easy (couple of weeks of work) to get the Moonlight engine to run on the Mac. Doing the gateway to the browser might be a few more weeks.
Miguel.